Air-cooling system



Feb. 16 1926. 1,573,641

` u. H. HUNT AIR COOLING SYSTEM Filed May 26, 1923 Patented Feb. 16, 1926.

UNITEDSTATES PATENT OFFICE.

JOHN H. HUNT, OF DAYTON, OHIO, ASSIGNOR TO GENERALIOTORS RESEARCH COR` PORATION, OF DAYTON, OHIO, A CORPORATION OF DELAWARE.` I

Am-coonme SYSTEM.

Application filed May 26, 1923. Serial No. 641,617.

To all whom t may concern.' Be it known that I, JOHN I-I. HUNT, a citizen of the United States of America, residing at, Dayton,'county of Montgomery, l and State of Ohio, have invented certain new and useful Improvements in Air-Cooling Systems, of which the following is a full, clear, and exact description. l

This invention relates to vair-cooled intermal-combustion engines, and particularly engines for automotive vehicles.

It is among the objects of the invention to control the air cooling of the engine in accordancewith engine temperature and temperature of the surrounding atmosphere.

Further objects and advantages of the present invention will be apparent from the following description, reference beingA had to the accompanying drawings, wherein preferred forms of embodiment of the present invention are clearly shown.

In the drawings: Figure 1 is; a view showing a .multiple cylinder internal combustion engine in side elevationand equipped with cooling means in accordance with my invention, the hood which encloses the engine and various of the elements for directing the flow of air past the same being shown in section. Figure 2 is a view showing a thermostat made use of in my invention, 1n plan.

Figure 3 is a fragmentary view upon a larger scale than Figure 2,`and showing a detail of the thermostat.

In the drawings 20 designates as a whole an internal-combustion 'engine including a plurality of cylinders with cooling' ribs or fins 22 which are partly enclosed by draft tube 23, for directin the circulation of air preferably toward a an 24 of the peripheral discharge type which is rotatably supported by and driven by the engine in anyconvenient manner as by means of afan pulley 25 and belt 26 connectedY with an engineY pulley not shown. The engine cylinders are preferably grouped in pairs and each pair of cylinders is connected at the top by means of a superstructure 30 which provides intake and exhaust ports of the engine, and supports the valves, rocker arms and valve springs. These superstructures areutilized for supporting a thermostat' which controls the circulation of air through the draft tube 23.

5 The drafttube 23 is provided with an outbetween brackets 50 and l53 has 'been pro- 'tached to a. rod 62 of aluminum orothery let frame or body 31 divided by a plurality of cross bars 32 into a plurality of air passages 33 all of which are in communication with the fan inlet 34. The fan outlets are provided by the. spaces between the fan blades 35. For further details of the fan, reference is made to the co-pending application of Charles F. Ketterin and Charles R. Short, Serial No, 553,938, edApril 17, 1922. Each of the air passages 33 is controlled by a shutter 36 pivoted at 37. All of the shutters are connected 'by a link 38 and the top shutter is provided with an arm 39 connected by a link 40 with an arm 41 attached to4 a thermostat which will now be described. L

The left handy superstructurer includesa l bracket'42 provided vwith ears 43 for supporting a shaft 44 attached at one end to the lever arm 41 'and loosely attached to sleeves 45 each attached to a rod 46 of Invar or other material having a very small coeflicient of expansion. IIhe other ends of rods 46 are connected by collars 47 loosely carried by a rod 48` which is supported' by ears 49 provided by a bracket 50. Bracket 50 is provided with slots 51 for receiving screws 52 passing loosely through the slots 5 1 and threaded into a bracket 53 provided. by the right hand superstructure 30. The heads of screws 52 are not tightened down upon the bracket 50 but are spaced abovebracket 50. A washer 54 and a spring 55 are located between the head of each screw 52 and the bracket'50. Endwise expansion of the engine will tend to change the distance between brackets 42 and 53, but the distance between shafts 44 and 48 cannot change materially. Therefore the sliding connection vided in order to provide for this difference 1n expansion.

Shaft 44 is provided intermediate itsends with a crank 60 supporting a sleeve 61 at m material. having a relatively great co-eicient of expansion. The other end of rodv 62 is connected by,a collar 63 loosely supported by the rod 48. A

When the'engine isrrelatively lcold the shutters 37 are closed. Due tothe heatingv of the engine the rod 62 will e and rela-A tively to the rods 46 causing the s aft 44 to be rotated counter-clockwise and the `link v40 to be moved to the left as viewed in Fig. 2, 110

thereby opening the air passages 33 in order that the fan 24 may be effective to draw cooling air past the engine cylinders and superstructures.

Where the engine is used in an automotive vehicle, it is generally enclosed by a hood 7 O provided at the front with a plurality of air inlets 7l and at its sides with a plurality of louvres 72 for the exit of heated air issuing from the fan and swept out of the hood by the cooler air which enters the hood during the motion of the vehicle.l Each air inlet 71 is vprovided with a shutter 73 pivoted at 74. All of the shutters 73 are connected by a link 75, and one of the shutters is provided with an arm 76 connected by a link 77 with a lever 78 pivoted at 79 upon a bracket 8() secured by screws 8l to the engine frame. Lever 78 is attached to the free end of a metal bellows 82 supported by the engine frameand partly illed with a temperature responsive volatile liquid such as ether. The bellows 82 is mounted substantially in alignment with the stream of air indicated by arrows 83 issuing from the fan 24. The bracket 80 is wide enough to protect the bellows 82 from direct contact with air entering the hood so that bellows 82 will not be directly responsive to the temperature of air entering the hood.

When the temperature of the surrounding atmosphere is relatively low the shutters 73 are closed, but, as the temperature of the air issuing from the fan 24 increases, the bellows 82 will expand causing the shutters 73 to open to permit air to enter at 7l. During the motion of the vehicle, the air entering at 71 will sweep out, through the louvres 72, the hot air issuing from the fan 24 and will also provide relatively cool air for circulating upwardly along the cylinders and into the draft tube 23 as indicated by the arrow 84.

The cooling of the engine may be controlled by means of both of the temperature responsive devices disclosed herein. VJhen the engine and outside air temperatures are relatively low, both sets of shutters 36 and 73 are closed. As the engine warms up the shutters 36 open first. Then the fan 24 discharges warm air against the thermostat 82 causing the shutters 73 to be opened to permit cooler air to enter the hood 7 O and sweep out the warm air from the fan 24 and to supply cooler air to the cylinders as already explained.

in warmer weather one or both of the shutters may be partly open before the engine is started depending on the temperature of the surrounding atmosphere.

lt is apparent that the cooling system for which the present invention is adapted, includes two air conduits, one of which encloses the other, namely: the hood 70 provides an air conduit which encloses the conduit provided by the draft tube 23 and fan 24. The entrance to the iirst conduit is controlled primarily in accordance with the temperature of the air issuing from the fan, and the passage of air through the second conduit is controlled primarily in accordance with engine temperature. Indirectly the flow of cooler air into the hood is controlled in response to engine temperature, because the hotter the engine, the hotter will be the exhaust from the fan.

In other words the air-cooling system disclosed herein includes a duct, the hood 70, through which air is caused to circulate by the motion of the vehicle propelled by the engine, and a second duct within the first duct through which air is caused to circulate by engine driven means, the fan 24. The first duct supplies the second duct with cooler air and sweeps out the exhaust from the second duct. The flow of cooler air into the lirst duct is controlled directly by the temperature of the exhaust from the second duct and, indirectly, the flow of air into the first duct is controlled by engine temperature since the exhaust from the fan is controlled by engine temperature.

Both thermostats are responsive to atmospheric temperature to the extent that both shutters may be partly open before the engine starts, depending on outside temperature. 1

Therefore, the present invention provides in a very simple manner an effective control of air circulating system and one which enables the engine to be quickly warmed up and then maintained at a temperature which is consistent with efficient operation.

`While the forms of embodiment of the invention as herein disclosed, constitute preerred forms, it is to be understood that other forms might be adopted, all coming within the scope or" the claims which follow:

lVhatl claim is as follows:

1. Apparatus for controlling the air cooling of an engine, comprising the combination with means for conducting air to the cylinders and means for conducting air away from the cylinders; of separate and independent temperature responsive devices each for controlling the How of air through one of said air conducting means.

2. Apparatus for controlling the air cooling of an engine, comprising the combination with means for conducting air to the cylinders and means for conducting air away from the cylinders; of temperature responsive means for controlling the flow of air to the cylinders; and a separate and independent device responsive to engine temperature for controlling the flow of air away from. the cylinders. y

3. Apparatus :tor controlling the air cooling of an engine, comprising the combination with means `for conducting air to the from the cylinders; of a device responsive I to temperature of air flowing from said cylinders for controlling the flow of air to the cylinders; and a device responsive to engine temperature for controlling the fiowjof air away from the cylinders.

4. Apparatus for controlling the air cooling of an engine, comprising the combination kwith means Afor conducting air to the cylinders and means for conducting air away from the cylinders; of la, device `responsive tmthe temperature of air owing from the cylinder for controlling the flow of air to the cylinders; and a temperature responsive device for controlling the flow of air away from the cylinders.

5. Apparatus for controllingthe air-cooling of an engine, comprising the combination withl a draft tubenfor conducting air about the engine, and a fan for drawing air through the draft tube; of means responsive to the temperature of air issuing from'the fan for controlling 6.' Apparatus for controlling the air cooli ing of an engine for propelling a vehicle the temperature of air .flowing into-the draft tube.

sponsive to temperature of air discharged by the first means for controlling the flowA of air through said second means.

7. Apparatus for controlling the air cooling of an engine for propelling avehicle comprising the combination with engine operated means for circulating airfabout the engine cylinders, andmeans rendered operative by vehicle motion for circulating air about the engine to supply cooler air to the rst means and to remove the warmer air discharged by the first means; of means responsive to temperature of air discharged by the first means for controlling the iow of air through said second means; and means responsive to the en ine temperature for controlling'the operatlon of the first means.

8. Apparatus for controlling the air cooling of a multiple cylinder internal combustion engine, comprising the combination withy a draft tube enclosing the engine cylinders and means for causing air to circulate through the draft tube; of temperature responslve means for controlling the passage of air through said draft tube and including a thermostat supported by cylinders, one end of said thermostat being fixed-and the other loose lrelativer to said cylinders so that said themostat will be unaffected by engine expansion.

4In testimonywhereof I hereto acliix my sig- 65 nature.

JOHN H. HUNT. 

